US3817751A - Color forming agents for the peroxide color intensifying process - Google Patents

Abstract

PROCESS FOR THE PRODUCTION OF PHOTOGRAPHIC DYE IMAGES BY IMAGEWISE DECOMPOSITION OF PEROXIDE COMPOUNDS IN THE PRESENCE OF REACTANTS FOR A COLOR FORMING OXIDATION COUPLING REACTION WHEREIN THE REACTANTS ARE ORGANIC COMPOUNDS WHICH CONTAIN A CN SINGLE OR DOUBLE BOUND AND IN WHICH THE CARBON ATOM IS SUBSTITUTED WITH A HYDROXY-OR AMINO-SUBSTITUTED ARYL GROUP AND THE NITROGEN ATOM IS SUBSTITUTED WITH A HYDROXY-OR AMINO-SUBSTITUTED ARYL GROUP OR IS A RING MEMBER OF A HETEROCYCLIC SATURATED OR UNSATURATED 5-OR 6-MENBERED RING.

Description

United States Patent date 3,817,751 COLOR FORMING AGENTS FOR THE PEROXIDE COLOR INTENSIFYING PROCESS Reinhart Mateiec and Walter Puschel, Leverkusen, Germany, assignors to Agfa-Gevaert Aktiengesellschaft, Leverknsen, Germany No Drawing. Filed Apr. 21, 1972, Ser. No. 246,387 Claims priority, application Germany, Apr. 24, 1971,

P 21 20 091.9 Int. Cl. G03c 1/00 US. Cl. 96-48 R 2 Claims ABSTRACT OF THE DISCLOSURE Process for the production of photographic dye images by imagewise decomposition of peroxide compounds in the presence of reactants for a color forming oxidation coupling reactiion wherein the reactants are organic compounds which contain a CN single or double bond and in which the carbon atom is substituted with a hydroxyor amino-substituted aryl group and the nitrogen atom is substituted with a hydroxyor amino-substituted aryl group or is a ring member of a heterocyclic saturated or unsaturated 5- or 6-membered ring.

The invention relates to a process for the production of photographic images by imagewise decomposition of peroxide compounds in the presence of compounds for a color forming oxidation reaction.

The production of photographic images by imagewise production of compounds which catalyse the decomposition of peroxide compounds followed by imagewise formation of dyes by oxidative coupling is known per se. By catalytic decomposition is meant here the catalytic activation of the peroxide which is required for the color forming oxidation reaction.

In this process a light-sensitive layer is exposed imagewise to produce in imagewise distribution nuclei of noble metals of Groups Ib and/or VIII of The Periodic Table. The layer containing the nuclei is then treated with peroxide compounds which decompose cataltyically at the nuclei in the image areas in the presence of reactants for a color forming oxidation reaction.

Instead of using light-sensitive layers which on exposure form metal nuclei which will decompose peroxide compounds, the layers used for the above mentioned process for the production of photographic images may contain substances which yield other peroxidase active catalyst on exposure. Suitable for this process are, for example, certain complex compounds of heavy metals of Groups VIb, VIIb and VIH of The Periodic Table with a monobasic or polybasic carboxylic acid or other ligands. Compounds which split off iodine ions on exposure to light I have the same effect.

The process may also be carried out with light-sensitive photographic materials which contain, uniformly distributed, catalase active enzymes such as catalase, peroxidase, haemoglobin or haemin which are inactivated in the image areas when exposed to actinic light. Direct positive images are obtained with these materials.

It is among the objects of the present invention to improve the above described process for the production of photographic dye images by means of new reactants for the oxidative coupling reaction, in order to increase in velocity of dye formation, the color density and the stability of the dye image.

We now have found a process for the production of photographic images including the steps of imagewise ex- Patented June 18, 1974 posing a light-sensitive layer to form nuclei which decompose peroxide compounds followed by treatment with catalytically decomposable peroxide compounds in the presence of reactants for a color forming oxidative coupling reaction wherein the color forming reactants are organic compounds which contain a CN single or double bond and in which the carbon atom is substituted with a hydroxy-substituted or amino-substituted aryl group and the nitrogen atom is substituted with a hydroxy-substituted or amino-substituted aryl group or is a ring member of a heterocyclic saturated or unsaturated 5- or 6-membered r-mg.

Reactants of the following general formulae have proved to be especially suitable:

R: Rih Ric-1i i l I I wherein R -=aryl substituted with hydroxyl and/or amino groups, especially phenyl, which aryl groups may also contain additional substituents, e.g. alkoxy having up to 18 preferably up to 5 carbon atoms, halogen such as chlorine, bromine or iodine, alkyl groups having up to 18 and preferably up to 3 carbon atoms, sulfo, esterified sulfo, carboxyl or esteri-fied carboxyl or nitrile;

R =hydrogen, alkyl having up to 18, preferably up to 5 carbon atoms which may contain additional substituents, e.g. carboxyl or hydroxyl or aryl, in particular phenyl in which the phenyl ring may contain the substituents listed under R R and K, have the same meaning as R R has the same meaning as R or alternatively R and R and/or R and R may also denote the ring members required to complete a heterocyclic saturated or unsaturated S-membered or 6-membered ring which contains nitrogen.

The nitrogen atom of the CN-bond in the above formulae may be present in quaternized form.

Particular utility is exhibited by the following compounds:

1 HO CH=N NH Mag? a. cm

ACE.

n on-Q01; cm

' OCH: 5

(ll-@CHNHO H NH: (all Br CHZNH NH: 0H 19 9 (|)H CHzNH NH: OH 20 CHzNH NH: OH 21 11 OH (3H CHzNH NH: H

CHzNH OH: 5 NH! OHJZ 23 CHzNH OH CHzNH OH @OHMHO NH: N H2 0H @CHMHO NH: CHa-flT-CH:

0H @CIHNHU l I N H: Czfla-N-CzH;

o H @4: Hump-O I NH: N HI CHzNH CH;

( n: 34 011 e CHQIII CH2N\/\/S 01 NH, 011 NH:

()H 1 CH2NH NHCH CHzN 0H Q NH, NH:

15 35 OH NH: OH I CIJH oH2 CH2I| OH I NH: H

NH: 0H 37 OH The above compounds are prepared by known processes. The preparation of some of these compounds is described in detail below; the others are obtained by analogous methods.

Compound 1 7.3 g. of vanillin and 5.6 'g. of 4,4'-diamino-diphenylaminosulfonic acid-(2) in 50 ml. of pyridine with the addition of 5 ml. of triethylamine are heated on a steam bath for one hour. Pyridine is distilled off under vacuum and the residue is redissolved in 25 ml. of pyridine whilst hot. After cooling,

100 ml. of isopropanol are added and the reaction mixture is filtered over active charcoal.

50 ml. of glacial acetic acid and 100 ml. of isopropanol are added to the filtrate. After one hour, the filtrate is suction-filtered and immediately stirred up with water.

Compound 4 g. of vanillin and 8.1 g. of 4,4'-diaminodiphenylamine in 100 ml. of pyridine are heated on a steam bath for 30 minutes with stirring. The reaction mixture is filtered whilst hot and the pyridine is distilled off under vacuum. The residue is triturated with ethyl acetate and again suction filtered.

Yield: 12.5 -g.; M.P.: l94-196 C.

The preparation of compounds 6-43 has been described in British Patent Specification No. 1,210,417.

The compounds disclosed in US. Patent Specification No. 3,535,114 are also suitable; compound 45 is an example thereof.

Some of the above compounds are already known as photographic developing agents. Of course one can only use compounds as photographic developing agents which have a suitable redox potential in the required pH region, i.e. which are capable of reducing silver halides to metallic silver.

The use of these substances for the purpose of the invention is completely different from their known use as photographic developers. According to the invention, these substances are used as reactants for a color forming coupling reaction which requires the decomposition of the peroxide compound as oxidizing agent. The oxidative coupling reaction has nothing whatever to do with the photographic devolopment of exposed silver halide. Consequently, when these substances are used in accordance with this invention, they are not required to satisfy any conditions as regards their activity within certain, relatively narrow pH ranges.

However for catalytic dye formation the color forming agents must also satisfy certain requirements as regards their electrochemical properties. Thus, they should have an auodic redox potential which is more negative at the pH values employed than the cathodic redox potential of the peroxide compound used, with the additional requirement that the difference between these two redox potentials must not exceed the value which corresponds to the activation energy required for the (non-catalytic) decomposition of the peroxy compound. However, these activation energies (and hence also the permissible potential dilferences) are very high and furthermore it is possible by suitable choice of various inorganic and/or organic peroxy compounds to cover an almost unlimited range of potentials. Hence even those compounds of structural formulae (I) and (II) which are not operative as photographic developers are suitable for use as color forming agents for the catalytic dye formation.

These substances which cannot be used as photographic developers yield, for example, brownish black to black dyes by catalytic dye formation on the image silver by decomposition of the peroxy compound, in particular H 0 The substances for use according to the invention may also be used in admixture with other reactants, e.g. pyrocatechol, resorcinol, orthoand para-phenylene diamines, diamine, N-allyland N,N-dialkyl-phenylenediamine. Further improvement in dye formation can thereby be obtained. These substances have been described e.g. in British Patent Specification No. 1,268,126 or US. Ser. No. 881, 610 now US. Pat. No. 3,674,490.

Production of the photographic images may be carried out in various ways by known methods. It is practically immaterial which peroxides active catalysts distributed in accordance with the image are used for the imagewise activation of the peroxide compound. It is preferred to use layers which upon exposure produce imagewise nuclei of noble metals of the Groups IB and/or VIII of The Periodic Table which in turn catalytically accelerate the decomposition of the peroxide compound. Photographic materials of this kind have been described in the above British Patent Specification.

Another suitable method of decomposing peroxide compounds imagewise has been described in British Patent Application No. 46,694/70 and US. Patent Application Ser. No. 74,482. The said Patent Applications relate to a light-sensitive material which contains compounds which on exposure to light form catalase active and/or peroxidase active catalysts. These are complex compounds of metals of Groups VIB, VIIB or VIII of The Periodic Table of Elements.

A similar material has been described in British Patent Application 57,633/70 and US. Patent Application Ser. No. 94,573 now US. Pat. No. 3,684,511. According to the said Patent Applications, the light-sensitive layer contains a compound which splits oft catalase active or peroxidase active iodine ions on exposure to light.

vAnother possible method has been described in British Patent Application No. 51,141/70 and US. Patent Application Ser. No. 84,195 now US. Pat. No. 3,694,207. The material described there enables direct positive images to be produced. The light-sensitive layer contains catalase active and/or peroxidase active enzymes which are inactivated on exposure to light. The material is then treated with hydrogen peroxide, decomposition then taking place only in the areas which have not been struck by light.

Suitable peroxide compounds are e.g. inorganic peroxide compounds such as perborates, percarbonates, persilicates, perphosphates or persulfates. Organic peroxide compounds may also be used, e.g. benzoyl peroxide. Hydrogen peroxide is particularly suitable owing to its efiicient action and the ease with which it can be handled in the form of aqueous solutions. Especially useful are addition compounds v of hydrogen peroxide with organic compounds, especially urea, acid amides, polyhydroxyl compounds or amines.

EXAMPLE 1 5 litres of an 8% aqueous gelatin solution are added to 1 litre of a highly sensitive silver iodobromide gelatin emulsion (4.5 mol-percent/Agl). The mixture is adjusted to pH 5.5. 200 g. of compound 44 are then suspended in this mixture which is then cast on a support of poly- Bath I:

2 g. of 1-phenylpyrazolidone-3 25 g. of hydroquinone 100 g. of anhydrous Na SO 1 g. of polyethylene oxide wax made up to 1 litre with H adjusted to pH 11.5 with NaOH.

After brief washing, the layer is immersed for 10 seconds in a mixture of the following composition at 35 C.:

Bath II:

700 cc. of 30% aqueous H 0 300 cc. of isopropanol 5 cc. of acetone.

In this bath, a black dye image (negative of the exposure original) is produced catalytically on the image silver with the aid of the peroxide introduced into the layer.

The layer is finally stabilized and fixed by introducing it for seconds into a solution of the following composition at 35 C.:

Bath III:

100 g. of Na S O 2 g. of KSCN 20 g. Of A12(SO4)3 in 1 litre of H20 adjusted pH 12 with NaOH.

This bath HI stabilizes the dye image to such an extent that subsequent washing is not absolutely necessary. A brief final washing (e.g. 10 seconds) is recommended only if the images are to be stored for a long time (e.g. longer than 2 months).

The color density of the dye image can be increased by briefly heating the layer between bath H and bath III (e.g. by infra-red radiation for 10 seconds at about 80 C.).

EXAMPLE 2 Preparation of the light-sensitive material:

20 g. of green ammonium ferricitrate are dissolved in 80 cc. of water 6 g. of ammonium ferrioxalate are dissolved in 60 cc. of

water 5 g. of K Fe(CN) are dissolved in 50 cc. of water 1 g. of citric acid is dissolved in 10 cc. of water 12 g. of gelatin are dissolved in 200 cc. of water.

The above solutions are mixed together in red darkroom light and the mixture is cast on a support of cellulose triacetate. The thickness of the dried layer is about 10 to 20,. The layer is hardened in the usual manner, by addition of a 2 ml. of a 30% aqueous solution of formalin or mucochloric acid.

Processing: The dried layer is exposed imagewise behind a grey step in a conventional sensitometer (100 watt lamp, exposure time 10 seconds). It is then exposed to a water vapour atmosphere at about 80 C. for about 10 to 20 seconds and then hardened for 30 seconds by spraying water on it.

10 The layer is then introduced into a bath (I) ofthe following composition for 30 seconds:

Bath I:

500 cc. of 30% H 0 500 cc. of a saturated aqueous solution of l-phenylethanol 25 g. of the sodium salt of benzilic acid.

It is then treated for 30 seconds with Bath H:

16 g. (N,N-diethyl)p-phenylenediaminsulfate 20 g. of compound 1 9 g. of sodium sulfite made up to 1 litre with H 0 adjusted to pH 9.5 with K CO It is then stabilized by immersing it for 30 seconds into a solution of Bath HI:

25 g. of ZnSO -7H O in 1 litre of H 0 with citric acid/citrate buffer adjusted to pH 5.

A black negative image of the original is obtained.

EXAMPLE 3 A transparent support of cellulose triacetate is coated with a solution containing 6 ml. of a 10% aqueous solution of polyvinyl alcohol and 2 g. of TiO: reduced to a particle size of 0.3 to 0.4 pm. and 0.1 mg. of erythrosine as spectral sensitizer in 400 cc. of water. The layer is then dried.

The dried layer is exposed imagewise and then treated for 30 seconds in the following bath at 20 C.:

Bath I: 2% aqueous NaPd(C O solution.

After brief washing, the layer is introduced for 30 seconds into a solution of the following composition at 20 0.:

Bath H:

500 CC. 0f 30% H203 450 cc. of cyclohexanol 40 cc. of cyclohexanone and 10 cc. of ethyl methyl glycol.

The layer is then introduced for 30 seconds into a bath of the following composition at 20 C. to effect catalytic dye formation:

Bath 1H:

10 g. of compound 45 50 g. of pyrocatechol 9 g. of anhydrous Na SO made up to 1 litre with H O adjusted to pH 8 with Na CO The layer is finally stabilized by introducing it for 30 seconds into the following solution at 20 C.:

12 g. of lead acetate in 1 liter of H 0 (adjusted to pH 6 with acetate/acetic acid buffer). A deep black image of the original is obtained.

We claim:

1. In a process for the production of photographic images by imagewise exposure of a lightsensitive layer wherein noble metal nuclei are producible, producing in 'the layer in imagewise distribution nuclei of noble metals of Groups Ib and VIII of The Periodic Table of Elements capable of catalytically decomposing peroxy compounds,

treating the layer which contains the imagewise distributed noble metal nuclei in the presence of a color forming compound which on oxidation yields a dye, with a peroxy compound thereby catalytically decomposing said peroxy compound on the noble metal nuclei'and oxidizing said color forming compound to yield a dye image, wherein the improvement comprises the color forming compound is an organic compound having an anodic redox potential more negative than the cathodic redox potential of the 11 12 peroxy compound and containing a CN single or double 2. The process of claim 1, wherein the color forming bond according to the following formulae: component is reacted in admixture with other aromatic amines, phenols and/or aminophenols. R: Rifi R1 mil-1 km R -J:= 5 References Cited (I) n UNITED STATES PATENTS wherein 3,674,490 7/1972 Metejec 96 48 PD 3 503 744 3/1970 Itano 96-48 R R =aryl substituted with hydroxyl and/0r ammo groups R2=hydmgen, alkyl or and 10 3,697,275 10/1972 Hayakawa et al 9648 R 11: and}; have the same meimng as R RONALD H. SMITH, Primary Examiner as esame meamn as ()1? alternatively g 1 I. L. GOODROW, Assistant Examiner R and R and/or R and R may also denote the ring members required to complete a heterocyclic saturated 15 9688 90 R Us or unsaturated S-membered or 6-membered ring.